Sign post



FIG. 1 is a perspective view showing the front and left side of the sign post holder showing a bicycle locked thereto in phantom view;

FIG. 2 is a top view of the sign post of FIG. 1;

FIG. 3 is rear view thereof;

FIG. 4 is a right side view thereof with the left side view being a mirror image; and,

FIG. 5 is a bottom view thereof.

The broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a sign post, as shown and described. 